This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-048333, filed Feb. 25, 1999, the entire contents of which are incorporated herein by reference.
This invention relates to a method of manufacturing a semiconductor device, in particular, to a working method of a thin film such as an interlayer insulating film or a metallic wiring layer.
The manufacturing method of a semiconductor device generally involves the steps of depositing a plurality of layers comprising a plurality of materials on a semiconductor wafer, and patterning each of these deposited thin films into a desired pattern. This patterning step of thin films or a work film (a film to be worked or processed) is generally performed as follows. Namely, at first, a photosensitive material called resist in general is deposited on a work film formed on the surface of wafer to form a resist film. Thereafter, a predetermined region of the resist film is selectively exposed and then subjected to a developing process to remove the exposed or unexposed region of the resist film, thereby forming a resist pattern. Subsequently, the work film formed in advance on the substrate is dry-etched using this resist pattern as an etching mask, thereby forming a desired pattern of the work film.
It is demanded, in view of ensuring desired resolution, light exposure tolerance or focus tolerance at the time of patterning exposure, to make the film thickness of the resist film as thin as possible. As a result, it is now very difficult to secure a sufficient film thickness of the resist film to perform the etching of the work film.
In order to overcome this problem, there has been adopted a method wherein a mask material which is more resistive to etching than the resist is deposited on surface of a work film, and then, the resist pattern formed in advance is successively transferred to the mask film and then to the work film.
The mask material that has been conventionally employed includes, as the dry type that can be employed in a dry method, a metal film such as aluminum and a carbon film; and as the wet type that can be employed in a wet method, polysilane or an organic resin such as novolak resin and polyhydroxystyrene. Among them, the metal film and carbon film that can be formed in a dry method are disadvantageous in view of high manufacturing cost since a vacuum system is required in the deposition thereof. With respect to the materials to be employed in a wet method in the deposition thereof, polysilane is accompanied with the problem that since it contains an inorganic atom in its molecule, it is difficult to strip a residual mask material pattern that has been left after the working of a work film. In the case of the organic resin on the other hand, it is also accompanied with the problem that the etching resistance thereof is almost the same as that of the resist.
In the meantime, Japanese Patent Unexamined Publication H8-241858 discloses an anti-reflective film composed of an organic resin in which carbon particles are dispersed. According to the method disclosed therein, carbon particles are dispersed at first in an organic solvent to obtain a mixture, which is then coated on the surface of a wafer substrate, thereby forming an anti-reflective film. In this case, since carbon particles are not dissolved in the organic solvent, carbon particles may be precipitated on the surface of film of coating, thus making it difficult to obtain an excellent coating property. Further, according to this publication, carbon particles are dispersed in an organic resin with a view to improve the light absorbency at a wavelength of 248 nm used as an exposure light and, to inhibit the reflection of light from the underlying substrate by means of this thin anti-reflective film. It is required however, for the purpose of achieving an absorbency which is as possible as high at the ultraviolet region, to employ carbon particles which involve a xcfx80-orbit at carbon-carbon bond. However, the inclusion of this xcfx80-orbit leads to an increase of absorbency even to an alignment light, thus preventing the alignment light from passing through the mask material. As a result, it becomes difficult to detect an underlying pattern formed in advance on an underlying substrate.
As explained above, a mask material which is suited for use in the manufacture of a semiconductor device is not yet available at present.
Therefore, an object of the present invention is to provide a method of forming a pattern, which enables a work film to be worked while assuring an excellent anisotropic etching of the work film even if the film thickness of a resist film is reduced, by using a mask material which can be normally coated in a wet method, has a sufficient etching resistance and is capable of being removed by means of an ashing treatment.
Another object of the present invention is to provide a method of forming a pattern, which employs a mask material which is excellent in transparency to an alignment light, thereby making it possible to realize a high precision alignment in relative to an underlying pattern.
Namely, this invention provides a method of forming a pattern, which comprises the steps of;
forming a mask material layer on a work film by coating a solution containing at least one kind of a network carbon polymer having a repeating unit represented by the following general formulas (CP1) to (CP4) on the work film;
forming a resist film on the mask material layer;
forming a resist pattern by exposing the resist film to a patterning exposure light and by developing the exposed resist film;
forming a mask material pattern by transferring the resist pattern to the mask material film; and
forming a work film pattern by transferring the mask material pattern to the work film: 
wherein R is halogen atom, hydrogen atom or a substituted or unsubstituted hydrocarbon group; A is a polyvalent organic group; and o, p and q denote respectively a positive integer.
Further, this invention provides a method of forming a pattern which comprises the steps of;
forming a mask material layer on a work film provided with an underlying pattern indicating a position information by coating a solution containing at least one kind of a network carbon polymer having a repeating unit represented by the following general formulas (CP1) to (CP4) on the work film;
forming a resist film on the mask material layer;
detecting the position information of the underlying pattern existing right below the resist film;
exposing the resist film to a patterning exposure light after correcting a position of an exposure pattern on the basis of a result of detection of the position information; and
forming a resist pattern by developing the resist film which has been subjected to the patterning exposure: 
wherein R is halogen atom, hydrogen atom or a substituted or unsubstituted hydrocarbon group; A is a polyvalent organic group; and o, p and q denote respectively a positive integer.
Further, this invention also provides a method of forming a pattern which comprises the steps of;
forming a matrix pattern on a work film;
filling an opened space in the matrix pattern with a mask material layer containing at least one kind of a network carbon polymer having a repeating unit represented by the following general formulas (CP1) to (CP4) on the work film;
forming a mask material pattern by removing the matrix pattern; and
forming a work film pattern by transferring the mask material pattern to the work film: 
wherein R is halogen atom, hydrogen atom or a substituted or unsubstituted hydrocarbon group; A is a polyvalent organic group; and o, p and q denote respectively a positive integer.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.